What If? 2

1. Asking Absurd Questions Unlocks Real Science.

Trying to answer silly questions can take you through some serious science.

Curiosity drives discovery. The book explores ridiculous hypothetical questions, like filling the solar system with soup or catching a bird in a car, not just for fun but to reveal underlying scientific principles. These questions, while silly, require applying real physics, chemistry, and biology to find answers.

Serious science in silly scenarios. Concepts like triboelectric charging (why hair sticks to balloons), black hole physics, atmospheric optics (mirages), and human metabolism are explained through the lens of these absurd scenarios. The unexpected connections highlight how fundamental science applies universally, even to the most outlandish ideas.

Embrace confusion. The author encourages embracing confusion when faced with questions nobody is expected to know the answer to. This mindset allows for exploration, looking things up, and discovering that sometimes, even seemingly simple phenomena like static electricity are areas of cutting-edge research.

2. Extreme Scale Breaks Physics (and Everything Else).

If you shrink Jupiter and plop it down in the middle of your neighborhood, that hot, high-pressure hydrogen, with no gravity holding it together, would expand.

Gravity's immense power. Filling the solar system to Jupiter with soup creates a black hole extending past Uranus, demonstrating how immense mass warps spacetime. A house-sized Jupiter, freed from its own gravity, explodes violently due to its internal heat and pressure, showing that scale is crucial to stability.

Relativistic effects at speed. Speeding up Earth's rotation to a one-second day causes the equator to move at over 10% the speed of light, flinging material outward and creating an expanding disk of debris that sterilizes the solar system. This highlights how relativistic speeds fundamentally change physical outcomes.

Charge vs. Gravity. An Earth of protons and a Moon of electrons wouldn't just attract; the electrostatic repulsion within each body is vastly stronger than gravity. However, at such extreme densities, general relativity predicts the formation of black holes, demonstrating that gravity eventually wins over even immense electrostatic forces at cosmic scales.

3. Your Body is Surprisingly Fragile (and Resilient).

You wouldn’t die instantly—you might survive for a few milliseconds or even seconds.

Limits of human tolerance. The human body has surprising limits to acceleration (around 4-6 Gs sustained), cold (space is hot but you'd freeze), and heat (nanoseconds in the Sun's core are fatal). Even seemingly minor things like drinking blood can cause severe illness long before alcohol intoxication.

Vulnerability to environment. Standing near an ultracold object can condense liquid oxygen, a fire hazard. Inhaling dust, even if not mostly dead skin, is harmful to lungs. Pressure changes, whether from deep ocean dives or high-altitude suction tanks, can be fatal to marine life and dangerous to humans.

Resilience in specific contexts. While fragile in extreme scenarios, the body is resilient in specific ways. Lips don't wear away from kissing. Bones are hard to break all at once. Some jellyfish stings are harmless. The body is adapted to its typical environment, not cosmic or absurd hypotheticals.

4. Everyday Actions Ripple Outward.

Breathing all those tires probably isn’t great for us, and it’s not great for the environment, either.

Hidden environmental impact. The rubber worn off tires doesn't just disappear; it becomes microplastic pollution in air, water, and soil, impacting ecosystems and potentially human health. This highlights how common activities have widespread, often unseen, environmental consequences.

Waste heat adds up. While one open refrigerator's waste heat is negligible, billions running outdoors would significantly contribute to global warming by increasing CO2 emissions from power generation. Even seemingly small, inefficient actions scale up globally.

Absurd weather events. A global snowfall of six feet would require 10^23 snowflakes and bury cities. A rain of lemon drops and gumdrops would be a catastrophe, burying infrastructure, causing global drought, and potentially triggering a runaway greenhouse effect from the sheer volume of sugar.

5. Space is Mostly Empty, But Still Dangerous.

Even if you flew through edge-on, so you spent as much time as possible in the dense galactic disk, your odds of hitting a star would be only about 1 in 10 billion.

Vastness and emptiness. The Milky Way is so vast that flying blind through it gives you only a 1 in 10 billion chance of hitting a star. This emphasizes the incredible emptiness of space compared to our intuition.

Distant but influential objects. Despite the distance, massive objects like the Sun exert significant gravitational pull, vastly outweighing the collective pull of all spiders on Earth. Distant black holes like Cygnus X-1 are cool to "own" in hypothetical airspace, but their influence is negligible at Earth distances.

Unexpected hazards. Even in the vacuum, quantum fluctuations might blur vision for a massive Earth-sized eye. Falling anvils from space reach terminal velocity, which is still lethal. Stars, if you could somehow smell them without burning, would likely smell acrid due to ionized particles.

6. Simple Physics Hides Complex Behavior.

Light in the atmosphere doesn’t go in a perfectly straight line.

Light bends unexpectedly. Mirages and Fata Morgana illusions show how temperature and density gradients in the atmosphere bend light, making distant objects appear distorted or displaced. This demonstrates that even seemingly simple phenomena like light travel are more complex than a straight line.

Fluid dynamics limits. Pumping fluids through narrow openings is limited by choking effects like cavitation (boiling water under low pressure) or reaching the speed of sound. Trying to funnel Niagara Falls through a straw would require relativistic speeds and destroy the planet due to recoil and energy release.

Optical limitations. You can't use lenses or mirrors to make something hotter than the light source's surface due to the second law of thermodynamics and the conservation of étendue. This is why you can't start a fire with moonlight, no matter how big the magnifying glass.

7. History, Biology, and Society Shape the Absurd.

Most of us only see oil in its refined forms—kerosene, plastics, and the stuff that comes out of gas pumps—so it’s easy to imagine the source as some uniform black bubbly material that's the same everywhere.

Fossil fuels' complex origins. Oil, the source of plastic dinosaurs, comes mostly from ancient marine plankton and algae, not dinosaurs, though some terrestrial matter (including potential dinosaur remnants) can contribute. The chemical composition reflects a complex history of burial and transformation.

Societal constraints on scale. Building a billion-story building is limited not just by engineering (weight, wind, elevators) but also by cost and the lack of societal will to fund such a project. Even if possible, fitting everyone and materials would be an organizational nightmare.

Legal and biological loopholes. A theoretical legal loophole in Yellowstone might allow unprosecuted felonies (though authorities disagree). The economic value of insects is immense ($57 billion/year in the US), but dividing it equally per insect results in fractions of a penny, highlighting the disconnect between macro-economic value and individual contribution.

8. Building Big Things is Incredibly Hard.

If you make a building too big, the top part is heavy and it squishes the bottom part.

Material strength limits. Building structures like skyscrapers or mountains is limited by the material's ability to support its own weight. A billion-story building would collapse, and a 62-mile-high mountain would require an impossible volume of rock.

Gravity and rotation challenges. An Earth-Moon fire pole is impossible because Earth's gravity would tear it apart, and the difference in rotation speed between the Moon's orbit and Earth's surface would break the connection. Even a magical pole requires navigating immense gravitational forces and relative speeds.

Efficiency vs. Scale. While catapults could theoretically save fuel for airliners, the required runway length becomes impractical. Pumping a swing becomes less efficient on taller swing sets due to air resistance, limiting the achievable height despite increased effort.

9. Value is Relative, Especially When Absurd.

Even if Au Bon Pain conquers the planet and puts everyone to work for them from now until the stars die, they wouldn’t make a dent in the bill.

Absurd financial demands. A $2 undecillion lawsuit is impossible to pay, exceeding the total economic value ever produced by humanity and the value of Earth's crust in precious metals. Even a planet made of solid gold wouldn't suffice.

High value in small volumes. The most expensive way to fill a shoebox involves substances like pure LSD, plutonium (though dangerous), or specific pharmaceuticals, reaching values around $2 billion. This contrasts with bulk commodities like gold or even large amounts of cash.

Unexpected sources of value. The nutritional value of a human is about 110,000 calories, enough to feed a T. Rex for two days. The collective mass of bananas produced annually could fill all the world's churches only ankle-deep, suggesting people consume far less than their weight in bananas.

10. Time Travel is More Complicated Than You Think.

Inside a black hole’s event horizon, in a sense time stops flowing forward and starts flowing inward.

Time distortion near black holes. Within a black hole's event horizon, time behaves counter-intuitively, flowing inward towards the singularity, making escape impossible and converging all timelines.

Relativistic effects of speed. Speeding up Earth's rotation to a one-second day means the equator moves at relativistic speeds, causing time dilation effects and leading to rapid destruction.

Walking backward through history. Walking backward in time at a rate of 30 days per step from Austin to New York reveals history in reverse, from modern cities disassembling to ancient ecosystems reappearing. This journey highlights the vastness of human and geological history compressed into a walkable distance.

Last updated: August 15, 2025